Direct drive form roller for printing presses



Aug. 16, 1955 D. D. VANDERCOOK 2,715,362

DIRECT DRIVE FORM ROLLER FOR PRINTING PRESSES Filed July 21, 1951 2 Sheets-Sheet 1 T 5 1. .I M g m E 0 L W I m z ll l ll 1111 H 8 3- L mm H i i f Q W t D Q Fl WQ 1 M ll E m I ...Q fim Again in W .......W.W W -.@w Q w 3 \\S\\\\\\\\\\\\\\\\ g ,5 k Q W H.-W- T% T IIIIIIII Q :1 MmwN MN W w H Aug. 16, 1955 D. D. VANDERCOOK 2,715,362

DIRECT DRIVE FORM ROLLER FOR PRINTING PRESSES Filed July 21, 1951 2 Sheets-Sheet 2 15-7: ZL/"E TTZL [:7 T

Darla D. V522 oercooir 544% JZWM,W,%M @775 United States Patent DIRECT DRIVE FORM ROLLER FOR PRINTING PRESSES David D. Vandercook, Evanston, 111., assignor to Vandercook and Sons, Inc., Chicago, 111., a corporation of Delaware Application July 21, 1951, Serial No. 237,915

6 Claims. (Cl. 101-348) The present invention relates to a form roller assembly for distributing printing ink evenly along the surfaces of letter press forms during the printing operation.

In most conventional printing assemblies, the form rollers which distribute the ink along the letter press forms, as the forms are carried along the bed, are not directly driven. While direct drives have previously been employed for form rollers, such directly driven form rollers are feasible only where the rollers are of relatively small width. When form rollers of a substantial width are driven directly, as by means of a gear and rack arrangement, smearing of the ink upon the letter press forms ordinarily results due to the pulsating motion of the form rollers. In the case of half-tone forms, some of the dots making up the half-tone pattern have too much ink applied to them, while others are insufiiciently inked. To overcome this characteristic of printing presses, it has heretofore been common practice to employ the form rollers as idler rollers, and drive them by frictional contact with a driven metallic vibrator roll mounted on a doubly threaded screw shaft by means of which the vibrator roll oscillates along the shaft in frictional contact with the form rollers to drive the rollers and to redistribute the ink on the surfaces thereof.

The present invention provides a new type of form roller assembly which eliminates the pulsating motion of form rollers, and permits direct driving of the form rollers even though the form rollers may be of substantial width.

In general, the form roller assemblies of the present invention include a directly driven shaft, a cylindrical form roller having a resilient outer surface, and an elastic coupling means which transmits the rotary motion from the driven shaft to the resilient outer surface of the form roller while at the same time permitting relative angular displacement between the shaft and the form roller. The elastic coupling between the positively driven shaft and the form roller drives the form roller at a substantially uniform velocity while still permitting a certain degree of slippage between the surface of the form roller and the driven shaft. As a result, the letter press forms an ink evenly without smearing even when relatively wide form rollers are employed.

An object of the present invention is to provide a form roller assembly for printing presses which may be of substantial width without encountering problems of smearing due to pulsating motion associated with directly driven form rollers.

Another object of the present invention is to provide a coupling means for a form roller assembly which transmits torque from a positively driven shaft in the form roller assembly to the outer surface of the form roller, while permitting relative angular displacement between the shaft and the form roller.

Another object of the present invention is to provide an improved form roller assembly including a resiliently deformable torque transmitting means between a positively driven shaft and a resilient form roller surface.

2,715,362 Patented Aug. 16, 1955 Another object of the present invention is to provide an improved form roller assembly including yieldable torsion means for driving a resilient form roller.

A further description of the present invention will be made in connection with the attached sheets of drawings, which by way of preferred example, illustrate one embodiment of the present invention.

In the drawings:

Figure 1 is a plan view of the form roller section of a printing assembly, with one of the form rollers being shown in cross section;

Figure 2 is an end view with parts in elevation illustrating the means by which the form rollers of the present invention are directly driven;

Figure 3 is a cross-sectional view taken substantially along the line IIiIII of Figure 1;

Figure 4 is a cross-sectional view taken substantially along the line IVIV of Figure 1; and

Figure 5 is a view in elevation of the preferred form of torque transmitting means employed in the form rollers of the present invention.

As shown on the drawings:

Figure 1 illustrates the form roller section of a more or less conventional printing assembly, and includes a pair of horizontally extending frame members and 11 which form part of a retractible form roller assembly. A pair of form rollers 12 and 13 are rotatably mounted between the oppositely disposed frame members 10 and 11, and since the form rollers 12 and 13 will normally be identical, the description of the structure of one will suffice for both.

The form roller 12 is provided with a shaft 14 which is journaled for rotation within suitable bearing members located in the frame members 10 and 11. Similarly, the form roller 13 is driven by a shaft 15.

The means for positively driving the form rollers 12 and 13 in the type of assembly shown in the drawings includes a pair of gear wheels 16 and 17 which are keyed or otherwise secured to their respective drive shafts 14 and 15. The gear wheels 16 and 17 are, in turn, driven by a reciprocating rack 20 (Figure 2) having teeth 21 which mesh with the teeth of the gear wheels 16 and 17 during a part of the reciprocating cycle of the rack 20.

The present invention is particularly concerned with the novel construction of the form rollers which are best illustrated in Figures 1, 3 and 4. As shown in Figure l, the form rollers are spaced from the frame members 10 and 11 by a pair of collars 23 and 24 secured to the shaft 14 at opposite ends of form roller 12. The form roller itself consists of a hollow cylindrical casing 25 having a form roller surface 26 of a resilient material bonded thereto. Ordinarily, the resilient material is cast about the cylindrical casing 25. The form roller surface 26 for the purposes of this invention, may be any soft, resilient material commonly employed in making form roller surfaces such as a synthetic rubber, for example, Neoprene, or any rubber-like or resinous material, as long as the material is substantially unaffected by printing inks and climatic conditions.

The open ends of the casing 25 are closed by means of a pair of oppositely disposed end collars 28 and 29, the latter being provided with sleeve bearings 30 and 31 respectively, to journal the shaft 14 for rotation therein. The casing 25 is mechanically coupled to the end collar 29 by means of a generally rectangular key 33 which is welded to the inner surface of the casing 25 and is tightly received within a keyway 34 provided in the end collar 29.

The preferred torque transmitting means of the present invention which couples the positively driven shaft 14 to the form roller surface 26 includes a restraining collar 36 and a sleeve bearing 37 carried thereby to ro-' tatably receive a portion of the shaft 14. To restrain movement of the restraining collar 36 and the bearing 37 along the axis of the shaft 14, the restraining collar 36 is secured to .a hollow cylindrical housing 38 as by means of a plurality of circumferentially spaced bolts 39. The opposite end of the cylindrical housing 38 is similarly secured to a reduced diameter annular portion 40 of the end collar 29 by means of a plurality of circumferentially spaced bolts 41.

As shown in Figures 1 and 3, the shaft 14 carries an elongated rectangular key 43 which may be press fit or welded into a longitudinally extending notch 44 along a portion of the shaft 14. Upon rotation of the shaft 14, the key 43 transmits the torque developed by the shaft to a pair of resiliently deformable cylindrical segments 45 and 46 (Figure 3 The cylindrical segments 45 and 46 are preferably composed of rubber or a rubber-like composition. As shown in Figure 5, the segments 45 and 46 are preferably grooved to provide an alternate series of lands 47 and grooves 48 in the cushioning segments. This construction is used to provide spaces for the rubber or rubber-like material of the segments 45 and 46 to accommodate compression of the segments during the intervals that they are in driving connection with the shaft 14.

The cushioning segments 45 and 46 are disposed concentric with the axis of the shaft 14 between the restraining collar 36 and the end collar 29. Assuming the direction of rotation of the shaft 14 of Figure 3 to be in a counterclockwise direction, initial rotation of the shaft 14 will cause the key 43 to compress the cushioning segment 46 and as soon as a sufficient binding action is built up, the segment 46 drives the restraining collar 36 and the end collar 29 by means of a key 55. As shown best in Figure 1, the key 55 is generally rectangular in shape and is provided with reduced end portions 48 and 49. The reduced end portion 48 is tightly received within a notch 50 formed in the restraining collar 36, while the opposite reduced end portion 49 is tightly received within a notch 51 formed in the reduced diameter annular portion 40 of the collar 29.

Thus, upon initial rotation of the shaft 14, no rotary motion is transmitted to the form roller surface 26 and a relative angular displacement occurs between the shaft 14 and the roller surface 26. Upon continued rotation of the shaft 14, however, the key 43 secured to the shaft compresses one or the other of the cushioning segments 45 and 46, depending upon the direction of rotation, causing the torque to be transmitted to the key 55. Since the key 55 is tightly held between the restraining collar 36' and the end collar 29, rotation of both these collars andthe cylindrical housing 38 will occur. As the key 55 drives the collars 36 and 29, the form roller casing 25 is also driven by virtue of the connection of the key 33 within .the slot 34 of the end collar 29. By virtue of this construction, the pulsating motion normally associated with the form rollers is eliminated by the cushioning members 45 and 46, so that the form roller surface 26 evenly distributes the printing ink on the letter press forms without smearing. By using the resilient coupling between the driven shaft and the form roller surface, form rollers of any width can be directly driven without encountering the smearing problem.

From the foregoing, it will be appreciated that the form roller assembly of the present invention has unique advantages over the form roller assemblies conventionally employed in printing presses. It should be noted that the resilient coupling means of the present invention are completely contained within the form roller assembly and require no adjustment. In printing assemblies in which the vibrator roll is used to supply motor power to the form rollers, there is always the necessity of adjusting the vibrator for proper height and the form rollers for position'and for height. In the present system, the vibrator roll can be positioned above and between the two form rollers so that it automatically settles rollers of said shaft, a resiliently deformable coupling means including a plurality of cylindrical segments of a resiliently deformable material concentric with said shaft and within said form roller, means interconnecting said shaft and saidsegments in driving connection, and means interconnecting said segments with said form roller in driving relation, whereby rotation of said drive shaft drives said form roller while permitting relative angular displacement between said shaft and said roller due to the inherent resiliency of said segments. a

2. In a form roller assembly for printing machines, a drive shaft, means for driving said shaft, a form roller including a hollow cylindrical casing mounted concentrically with said shaft, a resilient roller surface secured to said casing, a pair of collars closing the ends of said casing and journaling said shaft for rotation therein, means interconnecting said casing and one of said collars in driving connection, a resiliently deformable coupling means associated with said shaft and arranged to be driven thereby, and means interconnecting said coupling means and said one collar to transmit driving torque from said shaft to said roller surface while permitting relative angular displacement between said roller surface and said drive shaft due to the inherent resiliency of said coupling means.

3. In a form roller assembly for printing machines, a drive shaft, means for driving said shaft, a form roller including a hollow cylindrical casing mounted concentrically with said shaft, a resilient roller surface secured to said casing, a pair of collars closing the ends of said casing and journaling said shaft'for rotation therein, means interconnecting said casing and one of said collars in driving connection, a resiliently deformable coupling means associated with said shaft and arranged to be driven thereby, and a key secured to said one collar interconnecting said coupling means and said one collar to transmit driving torque from said shaft to said roller surface While permitting relative angular displacement between said roller surface and said drive shaft due to the inherent resiliency of said coupling means.

4. In a form roller assembly for printing machines, a

drive shaft, means for driving said shaft, a form roller including a hollow cylindrical casing mounted concentrically with said shaft, a resilient roller surface secured to said casing, a pair of end collars closing the ends of said casing and journaling said shaft for rotation therein, a key secured to said shaft, a pair of segmental cylin:

drical cushioning members engaging said key and arranged to be driven thereby, a restraining collar at one end of said segments confining said segments between said restraining collar and one of said pair of end collars,

a second key interconnecting said restraining collar and said one collar, :1 housing surrounding said segments, means securing said housing to said restraining collar and said one end collar, and a key secured to said casing,

and engaging said one end collar whereby rotation of said shaft transmits torque through said segments to said rollerv surface while permitting relative angular displace-.

ment between said roller surface and said drive shaft due to the inherent resiliency of said segments.

5. In a form roller assembly for printing machines, a shaft, means for driving said shaft, a cylindrical form roller having a resilient outer surface concentric with said shaft, elastic coupling means including a pair of cylindrical rubber segments having an alternate series of lands and grooves formed therein, means interconnecting said drive shaft with said segments to rotate said segments, and means interconnecting said segments and said form roller to transmit torque from said drive shaft through said segments to said form roller while permitting relative angular displacement of said form roller and said shaft due to the inherent resiliency of said segments.

6. In a form roller assembly for printing machines, a drive shaft, means for driving said shaft, a form roller having a resilient outer surface disposed along a portion of said shaft, a resiliently deformable coupling means including a plurality of cylindrical segments having an alternate series of lands and grooves formed therein of a resiliently deformable material concentric with said shaft, means interconnecting said shaft and said segments in driving connection, and means interconnecting References Cited in the file of this patent UNITED STATES PATENTS 534,676 Sperry Feb. 26, 1895 1,088,241 Royce Feb. 24, 1914 1,493,199 Havens May 6, 1924 1,759,542 Chn'stopherson May 20, 1930 1,904,764 Banker Apr. 18, 1933 

